The Investigator's Guide to Online Research & OSINT is an essential, practical reference for modern-day investigators, researchers, and analysts navigating the ever-evolving landscape of digital intelligence. Authored by former British Transport Police detective Tony Bennett, MSc, this comprehensive guide offers a UK-focused perspective on Open Source Intelligence (OSINT), blending professional experience with current best practices in online research and cyber investigations. Drawing on decades of experience in frontline law enforcement and high-tech crime units, Tony demystifies OSINT with clear, methodical instructions and real-world examples tailored for both beginners and seasoned professionals. Whether you're working in law enforcement, compliance, corporate investigations, journalism, or private research, this guide equips you with the tools to collect, verify, and analyse open-source data legally and ethically.